.mb {
    margin-top: 50px;
    width: 100%;
    height: 500px;
    background: url(./image/bannerbg.png) no-repeat;
    background-size: cover;
    overflow: hidden;
    display: flex;
    justify-content: space-between;
    align-items: center;

    .c_rig {
        background-color: white;
        height: 350px;
        width: 320px;
        padding: 10px;
        margin-left: 30px;

        >p {
            padding: 5px 0px;
        }
    }
}

.qbcg {
    margin-left: 640px;
}

.qq {
    width: 363px;
    border: 1px solid #ccc;
}

.qwer {
    padding: 0px 10px;

    >p {
        font-size: 10px;
        font-weight: bold;
    }
}

.nnn {
    height: 140px;
}

.m3 {
    margin-left: 50px;
    display: none;
}

@media (max-width:768px) {
    .m1 {
        display: none;
    }

    .m3 {
        display: inline-block;
    }

    .mb {
        flex-wrap: wrap;
    }

    .qbcg {
        margin-left: 200px;
    }

    .nnn {
        height: 300px;
    }
}